Suzanne Tracht makes a lovely lemongrass consomme for matzo ball soup. She starts with 2 whole chickens and throws them into a pot full of water with celery and some lemon grass. The lemon grass is prepared by crushing it with the back of a knife. She next adds a lime leaf, ginger, and a coarsely chopped onion. Finally, she adds garlic, red chilies, and white parts of leeks. She puts the pot onto the stove and brings it to a simmer. She is careful to lower the heat so it maintains a simmer and not a full boil. As scum comes to the top, skim it off and let it simmer for 30-40 minutes. Season it with salt and discard the chicken. Strain through a chinois and return to a simmer to use in your recipe. It should be flavorful and aromatic.